1. Field of the Invention
The present invention relates to a push button used in various fields, e.g., gaming machines such as slot machines, pachi-slot machines, pachinko machines (Japanese upright pinball gaming machines) etc., game controllers, keyboards for personal computers etc., mobile terminal devices, household electrical appliances, audio visual equipment, fixed-line phones, mobile phones, calculators, elevators, remote controllers etc.
2. Discussion of the Background
As an example of a push button, there has conventionally been known a push button that employs a photo sensor (e.g., refer to JP Laid-open patent application publication No. 2004-57380). In the above type push button, an output signal from a photo sensor is used for trigger switch between OFF and ON. Thereby, switch OFF and ON can be electrically carried out without mechanical contact.
In this connection, while the above such type push button was depressed for switch between OFF and ON, the balance between depression pressure needed for switch operation and reaction force against the pressure did not vary. This is because only the reaction force for returning the push button to its home position varies smoothly in accordance with the Hooke's law.
The present invention has been made to overcome the above mentioned problem and the object thereof is to provide a push button that uses an output signal from a photo sensor for trigger switch between OFF and ON wherein the balance between depression pressure needed for switch operation and reaction force against the pressure varies when switch between OFF and ON is carried out.